<?php 
session_start();
if(!isset($_SESSION['seed'])){
    $_SESSION['seed']=rand(0,999999999);
}
mt_srand($_SESSION['seed']);
$table = "abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
$pass='';
for ( $i = 0; $i < 24; $i++ ){
    $pass.=substr($table, mt_rand(0, strlen($table) - 1), 1);   
}
if(isset($_POST['password'])){
    if($pass==$_POST['password']){
        echo "<script >alert('恭喜你')</script>";
    }
}